Biopsies are good at helping diagnose cancer and its local spread. But once the biopsy and local excision is performed, there is no modality to monitor the state of cancer at the site. Now MIT researchers have developed an implantable probe that can continuously monitor the presence of a particular hormone produced by human tumor cells, and they hope their technology can be implemented for other cancer specific markers.
From an MIT press release:
In the Biosensors & Bioelectronics study, human tumors were transplanted into the mice, and the researchers then used the implants to track levels of human chorionic gonadotropin, a hormone produced by human tumor cells.
The cylindrical, 5-millimeter implant contains magnetic nanoparticles coated with antibodies specific to the target molecules. Target molecules enter the implant through a semipermeable membrane, bind to the particles and cause them to clump together. That clumping can be detected by MRI (magnetic resonance imaging).
The device is made of a polymer called polyethylene, which is commonly used in orthopedic implants. The semipermeable membrane, which allows target molecules to enter but keeps the magnetic nanoparticles trapped inside, is made of polycarbonate, a compound used in many plastics.
Cima [Michael Cima, MIT professor of materials science and engineering] said he believes an implant to test for pH levels could be commercially available in a few years, followed by devices to test for complex chemicals such as hormones and drugs.
Press release: Implantable device offers continuous cancer monitoring
Abstract in Biosensors and Bioelectronics: Implantable diagnostic device for cancer monitoring
